ETA: There is now a third thread, so send new comments there.
Since the first thread has exceeded 500 comments, it seems time for a new one, with Eliezer's just-posted Chapter 33 & 34 to kick things off.
From previous post:
Spoiler Warning: this thread contains unrot13'd spoilers for Harry Potter and the Methods of Rationality up to the current chapter and for the original Harry Potter series. Please continue to use rot13 for spoilers to other works of fiction, or if you have insider knowledge of future chapters of Harry Potter and the Methods of Rationality.
A suggestion: mention at the top of your comment which chapter you're commenting on, or what chapter you're up to, so that people can understand the context of your comment even after more chapters have been posted. This can also help people avoid reading spoilers for a new chapter before they realize that there is a new chapter.
One thing I do find myself wondering about this latest chapter is why neither of these two Most Brilliant Students (Hermione and Draco) seem to have thought of "Accio Broom!" or "Wingardiam Leviosa" instead of pursuing Harry with Gecko Gloves. If one or both of them is flying while Harry's got his hands stuck to a wall, they win. Also, since they've been fighting Chaos soldiers using hover charms to move while using ball bearings to make the floors impassable, they should have at least tried to adapt and use that strategy (granting that they can't use brooms or other means of flight due to rules of engagement or some such) when facing Harry on the roof. They need to work on their OODA Loops. ;)
Brooms are illegal magical artifacts, Wingardium Leviosa presumably too impractical because because it offers neither sufficient mobility to dodge nor allows for using cover so extended use (as opposed to using it just to pass obstacles) would make the levitated person an easy target (Harry can still cast with one hand while hanging on with the other and his feet), and would soon exhaust the levitating person as well. Besides they would be giving up their two to one advantage.